The code and name of the top language is returned. isReliable is True
if the top language is much better than 2nd best language.
textBytesFound tells you how many actual bytes CLD analyzed (after
removing HTML tags, collapsing areas of too-many-spaces, etc.).
details has an entry per top 3 languages that matched, that includes
the percent confidence of the match as well as a separate normalized
score.

The detect method takes optional params:

isPlainText (default is False): set to True if you know your bytes
don’t have any XML/HTML markup

includeExtendedLanguages (default is True): set to False to
exclude “extended” languages added by Google

hintTopLevelDomain (default is None): set to the last part of the
domain name that the content came from (for example if the URL was
http://www.krasnahora.cz, pass the string ‘cz’). This gives a
hint that can bias the detector somewhat.

hintLanguageCode (default is None): set to the possible language.
For example, if the web-server declared the language, or the
content itself embedded an http-equiv meta tag declaring the
language, pass this (for example, “it” for Italian). This gives a
hint that can bias the detector somewhat.

hintEncoding (default is None): set to the original encoding of
the content (note you still must pass UTF-8 encoded bytes). This
gives a hint that can bias the detector somewhat. NOTE: this is
currently not working.

pickSummaryLanguage (default is False): if False, CLD will always
return the top matching language as the answer. If True, it will
sometimes pick 2nd or 3rd match (for example, if English and X
match, where X (not UNK) is big enough, assume the English is
boilerplate and return X). In simple testing accuracy seems to
suffer a bit (XX to YY %) when this is True so I’ve defaulted to
False.

removeWeakMatches (default is True): if a match isn’t strong
enough, delete it. This ensures some amount of confidence when a
language is returned.

The module exports these global constants:

cld.ENCODINGS: list of the encoding names CLD recognizes (if you
provide hintEncoding, it must be one of these names).

cld.LANGUAGES: list of languages and their codes (if you provide
hintLanguageCode, it must be one of the codes from these codes).

cld.EXTERNAL_LANGUAGES: list of external languages and their
codes. Note that external languages cannot be hinted, but may be
matched if you pass includeExtendedLanguages=True (the default).

cld.DETECTED_LANGUAGES: list of all detectable languages, as best
I can determine (this was reverse engineered from a unit test, ie
it contains a language X if that language was tested and passes
for at least one example text).